- Molecular NameMethotrexate
- SynonymAmethopterin; Amethopterine; HDMTX; L-Amethopterin; Methopterin; Methotextrate; Methotrexat; Methotrexate Sodium; Methylaminopterin; Methylaminopterinum; MTX; N-Bismethylpteroylglutamic Acid
- Weight454.447
- Drugbank_IDDB00563
- ACS_NO59-05-2
- Show 2D model
- LogP (experiment)-1.08
- LogP (predicted, AB/LogP v2.0)-1.18
- pka3.8, 4.8, 5.6
- LogD (pH=7, predicted)-5.86
- Solubility (experiment)2.6 mg/ml
- LogS (predicted, ACD/Labs)(ph=7)-2.63
- LogSw (predicted, AB/LogsW2.0)0.02
- Sw (mg/ml) (predicted, ACD/Labs)0.0
- No.of HBond Donors7
- No.of HBond Acceptors13
- No.of Rotatable Bonds9
- TPSA210.54
- StatusFDA approved
- Administrationoral, IV, IM, SC, intrathecal
- PharmacologyAn antimetabolite and antifolate drug used in treatment of cancer and autoimmune diseases.
- Absorption_valueN/A
- Absorption (description)Oral absorption is saturatable and thus dose-dependent, with doses less than 40 mg/m2 having 42% bioavailability and doses greater than 40 mg/m2 only 18%. Mean oral bioavailability is 33% (13-76% range), and there is no clear benefit to subdividing an oral dose. Mean intramuscular bioavailability is 76%.
- Caco_2N/A
- Bioavailability59.0
- Protein binding46.0
- Volume of distribution (VD)0.55 L/kg
- Blood/Plasma Partitioning ratio (D_blood)N/A
- MetabollsmMethotrexate is metabolized by intestinal bacteria to the inactive metabolite 4-amino-4-deoxy-N-methylpteroic acid (DAMPA) and accounts for less than 5% loss of the oral dose.
- Half life7.2 h
- Excretionrenal 48~100%
- Urinary Excretion81
- Clerance2.1 ml/min/kg
- ToxicityBone marrow toxicity associated with concentrations >10 uM at 24 hours, >1 uM at 48 hours, or >0.1 uM at 72 hours after the dose.
- LD50 (rat)LD50=43mg/kg
- LD50 (mouse)N/A